The effects of optical phonon on the binding energy of bound polaron in a wurtzite ZnO/Mg{sub x}Zn{sub 1–x}O quantum well
- College of Physics and Electronic Information, Inner Mongolia Normal University, Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, Hohhot 010022 (China)
- Department of Applied Physics, College of Science, South China Agricultural University, Guangzhou 510642 (China)
- School of Physical Science and Technology, Inner Mongolia University, Hohhot 010022 (China)
An improved Lee-Low-Pines intermediate coupling method is used to study the energies and binding energies of bound polarons in a wurtzite ZnO/Mg{sub x}Zn{sub 1–x}O quantum well. The contributions from different branches of long-wave optical phonons, i.e., confined optical phonons, interface optical phonons, and half-space optical phonons are considered. In addition to electron-phonon interaction, the impurity-phonon interaction, and the anisotropy of material parameters, such as phonon frequency, electron effective mass, and dielectric constant, are also included in our computation. Ground-state energies, binding energies and detailed phonon contributions from various phonons as functions of well width, impurity position and composition are presented. Our result suggests that total phonon contribution to ground state and binding energies in the studied wurtzite ZnO/Mg₀.₃Zn₀.₇O quantum wells varies between 28–23 meV and 62–45 meV, respectively, which are much larger than the corresponding values (about 3.2–1.8 meV and 1.6–0.3 meV) in GaAs/Al₀.₃Ga₀.₇As quantum wells. For a narrower quantum well, the phonon contribution mainly comes from interface and half-space phonons, for a wider quantum well, most of phonon contribution originates from confined phonons. The contribution from all the phonon modes to binding energies increases slowly either when impurity moves far away from the well center in the z direction or with the increase in magnesium composition (x). It is found that different phonons have different influences on the binding energies of bound polarons. Furthermore, the phonon contributions to binding energies as functions of well width, impurity position, and composition are very different from one another. In general, the electron-optical phonon interaction and the impurity center-optical phonon interaction play an important role in electronic states of ZnO-based quantum wells and cannot be neglected.
- OSTI ID:
- 22306164
- Journal Information:
- Journal of Applied Physics, Vol. 116, Issue 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
Similar Records
ZnO/(ZnMg)O single quantum wells with high Mg content graded barriers
Optical properties of CdTe/Cd[sub 1-x]Zn[sub x]Te strained-layer single quantum wells